Pullulan, an exopolysaccharide consisting of maltotriose repeating units, has recently found many applications in different fields, such as food, packaging, cosmetics and pharmaceuticals. The introduction of photo-crosslinkable methacrylic units potentially allows to use pullulan derivative in inkjet 3D printing.
Pullulan was functionalized with methacrylic groups and the derivative was characterized by NMR, FT-IR and Raman spectroscopy. Water dispersions were thoroughly investigated by optical microscopy, SAXS and rheology to evaluate the self-assembly properties and they were used as photo-crosslinkable inks in a 3D printer, also in comparison with pristine pullulan. The structural and mechanical properties of the obtained films were studied by Atomic Force Microscopy and tensile strength tests.
The introduction of methacrylic groups moderately affects the self-assembly of the polymer in water, resulting in a slight increase of the gyration radius of the polymer coils and in a small decrease of the viscosity, retaining the typical shear-thinning behavior of concentrated polysaccharides in water. The structural and mechanical properties of the 3D printed films are much more affected, showing the presence of sub-micrometric phase segregated domains which are further separated by the cross-linking. As a result, the deformability of the materials is improved, with a lower tensile strength.
The introduction of methacrylic groups moderately affects the self-assembly of the polymer in water, resulting in a slight increase of the gyration radius of the polymer coils and in a small decrease of the viscosity, retaining the typical shear-thinning behavior of concentrated polysaccharides in water. The structural and mechanical properties of the 3D printed films are much more affected, showing the presence of sub-micrometric phase segregated domains which are further separated by the cross-linking. As a result, the deformability of the materials is improved, with a lower tensile strength.Replacing precious metal catalysts with low-price and abundant catalysts is one of urgent goals for green and sustainable energy development. It is imperative yet challenging to search low-cost, high-efficiency, and long-durability electrocatalysts for oxygen reduction reaction (ORR) in energy conversion devices. Herein, three-dimensional low-cost Co3Fe7 nanoparticles/nitrogen, manganese-codoped porous carbon (Co3Fe7/N, Mn-PC) was synthesized with the mixture of dicyandiamide, cobalt (II) tetramethoxyphenylporphyrin (Co(II)TMOPP), hemin, and manganese acetate by one-step pyrolysis and then acid etching. The resultant Co3Fe7/N, Mn-PC exhibited excellent durability and prominent ORR activity with more positive onset potential (Eonset, 0.98 V) and half-wave potential (E1/2, 0.87 V) in 0.1 M KOH electrolyte, coupled with strong methanol resistance. The pyrolysis temperature and optimal balance of graphite with pyridine-nitrogen are of significance for the ORR performance. The prepared Co3Fe7/N, Mn-PC displayed excellent ORR performance over commercial Pt/C in the identical environment. It was ascribed to the uniform 3D architecture, Mn- and N-doping effects by finely adjusting the electronic structures, coupled with the synergistic catalytic effects of multi-compositions and multi-active sites. This work provides some constructive guidelines for preparation of low-cost and high-efficiency ORR electrocatalysts.To test the applicability of "Gleiser and Hunt dental staging system modified by Kohler" (GHK) to assess third molar (3?M) development in a Russian population in order to determine the age of majority.
The sample consisted of 918 panoramic radiographs from Russian females (n?=?551) and males (n?=?367) within the age interval between 8 and 23 years. On each radiograph, 3?M development was classified based on the GHK technique. Statistics tested the data for normality. https://www.selleckchem.com/products/gcn2-in-1.html Mean age and standard deviation were described for each 3?M position. Ordinal logistic regression tested the performance of the technique to classify individuals below or above the 18-year threshold. Receiver Operating Characteristic (ROC) curves were used.
The mean ages and standard deviation (SD) for apex closure in females were 21,11 (SD?=?1,47), 21,11 (SD?=?1,43), 21,24 (SD?=?1,39), and 21,29 (SD?=?1,28) years for the teeth #18, 28, 38, and 48, respectively. Among males, the same teeth showed mean closure ages of 20,57 (SD?=?1,69), 20,64 (SD?=?1,76), 20,68 (SD?=?1,68), and 20,81 (SD?=?1,62) years, respectively. Area under the curve (AUC) reached 0.904 and 0.915 for classifying females and males below or above the 18-year threshold.
The GHK technique was able to describe 3?M development in a Russian population. The statistic model was able to classify individuals below or above the 18-year threshold. However, the outcomes must be carefully interpreted, especially in borderline cases (17-19-year spectrum).
The GHK technique was able to describe 3?M development in a Russian population. The statistic model was able to classify individuals below or above the 18-year threshold. However, the outcomes must be carefully interpreted, especially in borderline cases (17-19-year spectrum).The objective of this systematic review is to evaluate the role of mesenchymal stem cells in the regenerative treatment of temporomandibular joint resorption.
Search strategies were performed in the following databases PubMed/MEDLINE, EMBASE, Cochrane Collaboration Library, and Web of Science. Two independent reviewers selected the included articles using a two-phase process based on the eligibility criteria. The reviewers independently collected the required information from the included articles. The methodological quality of the selected studies was assessed individually.
In accordance with the inclusion and exclusion criteria, 703 studies were found and 8 articles were included. Thus, six studies using animal models and two human studies were included in this systematic review.
Based on the data of our systematic review, the use of mesenchymal stem cells is a promising method for the repair and regeneration of temporomandibular joint components.
Based on the data of our systematic review, the use of mesenchymal stem cells is a promising method for the repair and regeneration of temporomandibular joint components.